The present invention relates to heat pipes for use in releasing heat from heat evolving bodies in audio systems, copying machines, computers, etc.
Heat pipes heretofore known include those of the straight tubular type which comprise a container in the form of a straight tube and having water, Freon or like working fluid enclosed therein.
The performance of heat pipes (i.e.) the amount of heat transport, varies according to various factors, which include the kind of working fluid, the compatibility of the working fluid with the material of the container, the diameter of the container, the temperature of the heat insulating portion, the inclination of the heat pipe, presence or absence of a wick or groove, etc. Of these factors, the inclination of the heat pipe greatly influences the amount of heat transport as shown in FIG. 35 and FIG. 36. Especially small variations in the inclination of the heat pipe as positioned nearly horizontally greatly alter the amount of heat transport. Further as shown in FIG. 37, the amount of heat transport also changes greatly with the diameter of the container.
Audio devices and the like must essentially be lightweight and compact, and the container therefore needs to be reduced in both diameter and length. This presents difficulty in ensuring the required amount of heat transport. Furthermore, the heat pipe for use in such devices must generally be installed horizontally. This is also a great factor in causing a reduced amount of heat transport. Moreover, the amount of heat transport is greater when the working fluid is water than when it is Freon as will be apparent from FIGS. 35 and 36, so that water is used as the working fluid in the case where the heat pipe is installed horizontally. It is then impossible to use aluminum as the material for the container, necessitating the use of copper for the container. This makes it difficult to reduce the weight of the heat pipe.
In the case where the straight tubular heat pipe is used in audio devices or the like, a heat evolving body is attached to one end of the pipe, and the other end thereof serves as a condenser portion. It is then difficult to design the heat pipe so as to be accommodated in the case of the device since the heat pipe needs an increased length.